SECAUCUS, N.J. -- New York Red Bulls coach Juan Carlos Osorio resigned Friday and was replaced for the rest of the season by assistant coach Richie Williams.

Less than a year after playing for the Major League Soccer championship, the Red Bulls have the worst record in the league at 2-16-4.

The Red Bulls said a search for a new head coach would begin immediately.

"It has been a difficult season for Juan Carlos and he felt that it was in the best interest of the team to step aside," Red Bulls managing director Erik Stover said. "I want to personally thank Juan Carlos for his efforts with the Red Bulls organization. It was under his leadership last season that the team won the Western Conference Championship and reached the MLS Cup Final for the first time in franchise history. We wish him well in his future endeavors."

Osorio apologized to Red Bulls fans for the team's play this season.

"I want to thank the players for their hard work," Osorio said. "I would also like to thank the club for the opportunity to coach the team for the past two seasons."

Williams, 39, takes over as interim head coach for the second time in his four-year coaching career with the team. He also served as the Red Bulls interim head coach from June 27-Aug. 12, 2006, taking over for Mo Johnston and going 4-3-2 over that stretch.

Osorio joined the Red Bulls as head coach on Dec. 18, 2007. In his two seasons, he led the team to a 12-27-13 record and an appearance in the 2008 MLS Cup Final.

The Red Bulls' next match is Sunday against FC Dallas at Giants Stadium.